1 // SPDX-License-Identifier: GPL-2.0-only 2 /* Low-level parallel port routines for the Amiga built-in port 3 * 4 * Author: Joerg Dorchain <joerg@dorchain.net> 5 * 6 * This is a complete rewrite of the code, but based heaviy upon the old 7 * lp_intern. code. 8 * 9 * The built-in Amiga parallel port provides one port at a fixed address 10 * with 8 bidirectional data lines (D0 - D7) and 3 bidirectional status 11 * lines (BUSY, POUT, SEL), 1 output control line /STROBE (raised automatically 12 * in hardware when the data register is accessed), and 1 input control line 13 * /ACK, able to cause an interrupt, but both not directly settable by 14 * software. 15 */ 16 17 #include <linux/module.h> 18 #include <linux/init.h> 19 #include <linux/parport.h> 20 #include <linux/ioport.h> 21 #include <linux/interrupt.h> 22 #include <linux/platform_device.h> 23 24 #include <asm/setup.h> 25 #include <asm/amigahw.h> 26 #include <asm/irq.h> 27 #include <asm/io.h> 28 #include <asm/amigaints.h> 29 30 #undef DEBUG 31 32 static void amiga_write_data(struct parport *p, unsigned char data) 33 { 34 pr_debug("write_data %c\n", data); 35 /* Triggers also /STROBE. This behavior cannot be changed */ 36 ciaa.prb = data; 37 mb(); 38 } 39 40 static unsigned char amiga_read_data(struct parport *p) 41 { 42 /* Triggers also /STROBE. This behavior cannot be changed */ 43 return ciaa.prb; 44 } 45 46 static unsigned char control_amiga_to_pc(unsigned char control) 47 { 48 return PARPORT_CONTROL_SELECT | 49 PARPORT_CONTROL_AUTOFD | PARPORT_CONTROL_STROBE; 50 /* fake value: interrupt enable, select in, no reset, 51 no autolf, no strobe - seems to be closest the wiring diagram */ 52 } 53 54 static void amiga_write_control(struct parport *p, unsigned char control) 55 { 56 pr_debug("write_control %02x\n", control); 57 /* No implementation possible */ 58 } 59 60 static unsigned char amiga_read_control( struct parport *p) 61 { 62 pr_debug("read_control\n"); 63 return control_amiga_to_pc(0); 64 } 65 66 static unsigned char amiga_frob_control( struct parport *p, unsigned char mask, unsigned char val) 67 { 68 unsigned char old; 69 70 pr_debug("frob_control mask %02x, value %02x\n", mask, val); 71 old = amiga_read_control(p); 72 amiga_write_control(p, (old & ~mask) ^ val); 73 return old; 74 } 75 76 static unsigned char status_amiga_to_pc(unsigned char status) 77 { 78 unsigned char ret = PARPORT_STATUS_BUSY | PARPORT_STATUS_ACK | PARPORT_STATUS_ERROR; 79 80 if (status & 1) /* Busy */ 81 ret &= ~PARPORT_STATUS_BUSY; 82 if (status & 2) /* PaperOut */ 83 ret |= PARPORT_STATUS_PAPEROUT; 84 if (status & 4) /* Selected */ 85 ret |= PARPORT_STATUS_SELECT; 86 /* the rest is not connected or handled autonomously in hardware */ 87 88 return ret; 89 } 90 91 static unsigned char amiga_read_status(struct parport *p) 92 { 93 unsigned char status; 94 95 status = status_amiga_to_pc(ciab.pra & 7); 96 pr_debug("read_status %02x\n", status); 97 return status; 98 } 99 100 static void amiga_enable_irq(struct parport *p) 101 { 102 enable_irq(IRQ_AMIGA_CIAA_FLG); 103 } 104 105 static void amiga_disable_irq(struct parport *p) 106 { 107 disable_irq(IRQ_AMIGA_CIAA_FLG); 108 } 109 110 static void amiga_data_forward(struct parport *p) 111 { 112 pr_debug("forward\n"); 113 ciaa.ddrb = 0xff; /* all pins output */ 114 mb(); 115 } 116 117 static void amiga_data_reverse(struct parport *p) 118 { 119 pr_debug("reverse\n"); 120 ciaa.ddrb = 0; /* all pins input */ 121 mb(); 122 } 123 124 static void amiga_init_state(struct pardevice *dev, struct parport_state *s) 125 { 126 s->u.amiga.data = 0; 127 s->u.amiga.datadir = 255; 128 s->u.amiga.status = 0; 129 s->u.amiga.statusdir = 0; 130 } 131 132 static void amiga_save_state(struct parport *p, struct parport_state *s) 133 { 134 mb(); 135 s->u.amiga.data = ciaa.prb; 136 s->u.amiga.datadir = ciaa.ddrb; 137 s->u.amiga.status = ciab.pra & 7; 138 s->u.amiga.statusdir = ciab.ddra & 7; 139 mb(); 140 } 141 142 static void amiga_restore_state(struct parport *p, struct parport_state *s) 143 { 144 mb(); 145 ciaa.prb = s->u.amiga.data; 146 ciaa.ddrb = s->u.amiga.datadir; 147 ciab.pra |= (ciab.pra & 0xf8) | s->u.amiga.status; 148 ciab.ddra |= (ciab.ddra & 0xf8) | s->u.amiga.statusdir; 149 mb(); 150 } 151 152 static struct parport_operations pp_amiga_ops = { 153 .write_data = amiga_write_data, 154 .read_data = amiga_read_data, 155 156 .write_control = amiga_write_control, 157 .read_control = amiga_read_control, 158 .frob_control = amiga_frob_control, 159 160 .read_status = amiga_read_status, 161 162 .enable_irq = amiga_enable_irq, 163 .disable_irq = amiga_disable_irq, 164 165 .data_forward = amiga_data_forward, 166 .data_reverse = amiga_data_reverse, 167 168 .init_state = amiga_init_state, 169 .save_state = amiga_save_state, 170 .restore_state = amiga_restore_state, 171 172 .epp_write_data = parport_ieee1284_epp_write_data, 173 .epp_read_data = parport_ieee1284_epp_read_data, 174 .epp_write_addr = parport_ieee1284_epp_write_addr, 175 .epp_read_addr = parport_ieee1284_epp_read_addr, 176 177 .ecp_write_data = parport_ieee1284_ecp_write_data, 178 .ecp_read_data = parport_ieee1284_ecp_read_data, 179 .ecp_write_addr = parport_ieee1284_ecp_write_addr, 180 181 .compat_write_data = parport_ieee1284_write_compat, 182 .nibble_read_data = parport_ieee1284_read_nibble, 183 .byte_read_data = parport_ieee1284_read_byte, 184 185 .owner = THIS_MODULE, 186 }; 187 188 /* ----------- Initialisation code --------------------------------- */ 189 190 static int __init amiga_parallel_probe(struct platform_device *pdev) 191 { 192 struct parport *p; 193 int err; 194 195 ciaa.ddrb = 0xff; 196 ciab.ddra &= 0xf8; 197 mb(); 198 199 p = parport_register_port((unsigned long)&ciaa.prb, IRQ_AMIGA_CIAA_FLG, 200 PARPORT_DMA_NONE, &pp_amiga_ops); 201 if (!p) 202 return -EBUSY; 203 204 err = request_irq(IRQ_AMIGA_CIAA_FLG, parport_irq_handler, 0, p->name, 205 p); 206 if (err) 207 goto out_irq; 208 209 pr_info("%s: Amiga built-in port using irq\n", p->name); 210 /* XXX: set operating mode */ 211 parport_announce_port(p); 212 213 platform_set_drvdata(pdev, p); 214 215 return 0; 216 217 out_irq: 218 parport_put_port(p); 219 return err; 220 } 221 222 static void __exit amiga_parallel_remove(struct platform_device *pdev) 223 { 224 struct parport *port = platform_get_drvdata(pdev); 225 226 parport_remove_port(port); 227 if (port->irq != PARPORT_IRQ_NONE) 228 free_irq(IRQ_AMIGA_CIAA_FLG, port); 229 parport_put_port(port); 230 } 231 232 /* 233 * amiga_parallel_remove() lives in .exit.text. For drivers registered via 234 * module_platform_driver_probe() this is ok because they cannot get unbound at 235 * runtime. So mark the driver struct with __refdata to prevent modpost 236 * triggering a section mismatch warning. 237 */ 238 static struct platform_driver amiga_parallel_driver __refdata = { 239 .remove_new = __exit_p(amiga_parallel_remove), 240 .driver = { 241 .name = "amiga-parallel", 242 }, 243 }; 244 245 module_platform_driver_probe(amiga_parallel_driver, amiga_parallel_probe); 246 247 MODULE_AUTHOR("Joerg Dorchain <joerg@dorchain.net>"); 248 MODULE_DESCRIPTION("Parport Driver for Amiga builtin Port"); 249 MODULE_LICENSE("GPL"); 250 MODULE_ALIAS("platform:amiga-parallel"); 251